New luminescent copolyethers with diphenylanthracene-emitting segments and electron-transporting benzoxazole phenyl were successfully synthesized by aromatic nucleophilic substitution. The polymers, characterized by NMR and IR spectroscopy, were obtained in high yields, showed good solubility in various organic solvents, and had high thermal stability with high glass-transition temperatures (125-129). The number-average Molecular weights of the Polymers were 10,000-20,000, and they had polydispersity indices of 1.2-1.4. The optical and electrochemical properties of the polymers were also investigated. The pure blue emission for the polymers (maximum wavelength = 430440 run) was obtained with high photoluminescence quantum efficiency (76-78%) in a chloroform Solution. The blue electroluminescence for the poly(TDPB) (maximum wavelength 440 nm),vas obtained with a turn-on voltage of 1.5-20 V when simple light-emitting diodes (indium tin oxide/polymer/Al) were fabricated. (c) 2006 Wiley Periodicals, Inc.